1. The Field of the Invention
This invention relates to glass-reinforced concrete compositions, methods of preparing and applying such compositions, as well as a spray nozzle device used in applying such compositions. In another aspect, the invention relates to composite structural insulated panels, related methods of manufacture, and building systems employing such panels. Such panels may be formed from the disclosed glass-reinforced concrete compositions.
2. Background and Relevant Art
Glass fibers have been used in concrete compositions to provide increased strength. However, when applying a concrete composition by spraying, glass fibers have been found to plug the flow of material through the spray device. As a result of such difficulties, where it is desired to apply a concrete composition by spraying, the concrete composition without glass fibers is delivered through a spray nozzle, while a spool of glass fibers is simultaneously fed to a location adjacent where the concrete composition exits the spray nozzle, the glass fiber is cut, and the fiber segments are thus entrained within the concrete composition while being sprayed onto a desired surface.
In addition, it can be difficult to disperse the glass fibers into the concrete composition so that their orientation is randomized. Rather, they tend to be preferentially aligned in one direction, leading to non-uniform, directional strength characteristics. More uniform strength characteristics throughout the cured concrete, independent of direction, could be achieved if the orientation of the glass fibers were more randomized.
In addition, when applying a concrete composition by spraying, often the spray characteristics at any given moment may be less than desirable (e.g., the composition does not seem to flow well, etc.). Thus, the operator of the spray equipment will often attempt to improve the spray and flow characteristics of the concrete composition through the spray equipment by adjusting various parameters of the concrete mixture itself (e.g., addition of water). Such on the fly adjustments to the concrete mixture itself are problematic because they can drastically and negatively affect the strength characteristics of the final cured concrete product. As a result, while the operator may be content that he or she is able to deliver the composition by spraying, it is difficult to know whether the strength characteristics of the finished product will be sufficient for a given use. This is particularly problematic for applications that require high strength and uniformity of strength.
As a result, many finished products have insufficient strength for use, resulting in waste. In addition, as a practical matter, current compositions and methods do not readily allow one to manufacture several components intended to be used together to provide high, substantially uniform strength characteristics from one manufactured component to the next. This is because it is often not known exactly how parameters of the concrete composition were adjusted during spraying.
As a result, there exists a need for improved glass-reinforced concrete compositions having guaranteed uniform high strength characteristics, spray devices for delivering such compositions in a manner that would eliminate the need for the operator to adjust spray parameters on the fly, products manufactured using such compositions, and methods and equipment that would provide uniform, guaranteed high strength.